One of nine endocrine glands in the body, located in front of the neck just below the Adam's apple. It is shaped like a butterfly, with two lobes on either side of the neck connected by a narrow band of tissue. The thyroid gland produces thyroid hormones that set the rate the body carries on its necessary functions (metabolic rate). Some of the functions controlled by thyroid hormones include heart rate, cholesterol level, body weight, energy level, muscle strength, skin condition and vision.